Other mistake: When Sheriff Tucker shows Pam the newspaper clippings taken from Roy's wallet, plainly two of three columns in the article are identical and have nothing to do with Jason. (01:21:35)
Other mistake: After noticing that Tina is dead, Eddie fearfully backs away and leans against the tree. You can see Roy put the leather up and over the tree. This is impossible. He would have to whip it around the tree, not over it.